﻿using System;
using System.Security.Cryptography;
using System.Text;

namespace Donal.Xms.Common
{
    /// <summary>
    /// DES加密/解密类。
    /// </summary>
    public class DESEncrypt
    {

        #region ========加密========

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Encrypt(string Text)
        {
            return Encrypt(Text, "Donal.Xms");
        }
        /// <summary> 
        /// 加密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Encrypt(string Text, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray;
            inputByteArray = Encoding.Default.GetBytes(Text);
            des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            return ret.ToString();
        }

        /// <summary>
        ///  RSA公钥加密 加密文本
        /// </summary>
        /// <param name="encryptText">要加密的明文</param>
        /// <param name="publicKey">公钥</param>
        /// <returns>未加密数据的字符串</returns>
        public static string RsaEncrypt(string encryptText, string publicKey)
        {
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                try
                {
                    rsa.FromXmlString(publicKey);
                    var encrypted = Convert.FromBase64String(encryptText);
                    var bytes = rsa.Encrypt(encrypted, false);
                    return Encoding.UTF8.GetString(bytes);
                }
                catch
                {
                    return "";
                }
            }
        }


        #endregion

        #region ========解密========

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Decrypt(string Text)
        {
            return Decrypt(Text, "Donal.Xms");
        }
        /// <summary> 
        /// 解密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Decrypt(string Text, string sKey)
        {
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                int len;
                len = Text.Length / 2;
                byte[] inputByteArray = new byte[len];
                int x, i;
                for (x = 0; x < len; x++)
                {
                    i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                    inputByteArray[x] = (byte)i;
                }
                des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Encoding.Default.GetString(ms.ToArray());
            }
            catch
            {
                return string.Empty;
            }
        }

        /// <summary>
        ///  RSA 私钥 解密
        /// </summary>
        /// <param name="encryptedText">加密的密文</param>
        /// <param name="privateKey">私钥</param>
        /// <returns>未加密数据的字符串</returns>
        public static string RsaDecrypt(string encryptedText, string privateKey)
        {
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                try
                {
                    rsa.FromXmlString(privateKey);
                    var encrypted = Convert.FromBase64String(encryptedText);
                    var bytes = rsa.Decrypt(encrypted, false);
                    return Encoding.UTF8.GetString(bytes);
                }
                catch
                {
                    return "";
                }
            }
        }
        #endregion

    }
}
